#include<stdio.h>
int main(){
    int i=1;
    int sum_1=0;
    int sum_2=0;
    while(i<=100){
        if(i%2==0){
            sum_1=sum_1+i;
        }
        i=i+1;
    }
    printf("sum_1=%d\n",sum_1);

    return 0;
}
